The invention relates to a device for producing plastics parts having in each case at least one rod-shaped metal insert, in particular a medical puncture means, in an injection moulding process, comprising a first mould half element and a second mould half element, at least one of the mould half elements being movable along a closure direction (Z) such that in a closed position, the two mould half elements together form a closed cavity for moulding a plastics part, the insert projecting at least in portions into the cavity in order to be overmoulded with plastics material, and being substantially arranged between the two mould half elements in a mould dividing plane which comprises a longitudinal direction (X) and a width direction (Y).
Generic devices for producing plastics parts having in each case at least one rod-shaped metal insert, in particular a medical puncture means, in an injection moulding process are known from the prior art. Specifically in medical technology, very different inserts, such as needles, cannulas or the like are inserted into injection moulds in order to overmould them with plastics material in the cavity formed by the injection mould. The inserts are generally inserted into a lower mould half element of a vertical mould arrangement. However, it is also conceivable to use a horizontal mould arrangement. The plastics material is usually delivered to the cavity via one or more runners and passes into the cavity via a gate or a nozzle. After the insert has been overmoulded, the finished product, namely the plastics part having the insert, is ejected from the corresponding mould half element by an ejection apparatus and is removed from the injection mould by a removal apparatus. Usually, the mould half element comprising the nozzle is known as the injector side and the mould half element comprising the ejector is known as the ejector side.
Plastics parts having inserts specifically for medical uses, for example syringes, infusion sets, lancing aids and puncture elements of capsule inhalers, etc. are produced in this manner. Here, a very low tolerance of the needle or cannula respectively to the plastics part is often acceptable. When used on the human body in particular, inserts which are positioned outside this tolerance can cause severe pain or serious damage if a medical instrument does not function. Furthermore, faulty components of this type can damage medical instruments which make use of these components. Thus, the tolerance ranges in a production process of this type are extremely narrow, to be able to ensure the full functionality of every plastics part produced in this way. Even the smallest positional differences of an insert to be overmoulded can result in the fact that a medical plastics part cannot be used later on. Hence the requirement that the inserts which can have very small dimensions specifically in medical technology must be inserted in an extremely precise manner into the cavity of the injection mould.
Hitherto, attempts have been made to achieve these low tolerances by precise handling robots. However, such exact handling systems are very expensive and, from a performance point of view, are almost incapable of maintaining the required tolerances. Furthermore, there is a very high risk that after the inserts have been positioned correctly, the position thereof will change again because the insert cannot be fixed satisfactorily between the positioning procedure and the injection moulding process. Alternatively, inserts are often pushed onto a stop. However, since the above-mentioned articles such as needles and cannulas have very sensitive ground surfaces which are extremely critical for the function of a medical instrument, this is not feasible here. Thus, the distal ground surface would be destroyed when impacting a stop as it would by a slide which is to be pushed against this distal end.
Thus, the object of the present invention is to provide a device for producing plastics parts having in each case at least one rod-shaped metal insert, in particular a medical puncture means, in an injection moulding process, which device avoids the above-mentioned problems.